Plating fixture for gas cylinders of rifles



Nov. 2l, 1944. G, KALlsTA 2,363,005

PLATING FIXTURE FOR GAS CYLINDERS 0F RIFLES l Filed July l, l942 Gein-ja Kalista Patented Nov. 21, 19.44

George-Kalista, Spr'ng'fleld,"ll/klass; Application July 1,1942,'sennNelligan] I 2 claims.v-r (o1. zofi-,Azs'z-l (Granted under the yact llvf'lt'lartzhl 3. 118,83, .as n x amended Aprili30, 1928; 370.:0;G-17i57.)5 y

' Theinvention described herein may be marlu-V I factured and used by or for the Goverment for governmentalpurposes, without the payment to me of any royalty thereon. f

. This `invention lrelates to a plating fixture, particularly a fixture for plating the interior :bore surface of the gas cylinder of a rifle.

Plating the bore of a gascylinder of aV rie isat best a. diflicult procedure when conventional plating apparatus is employed vbecause the odd shape of the cylinder makes itextremelyhard tov yhold in the plating solution without the usey of a @special xture; A gas cylinder of the type tombe plated is a comparatively short tubular -member with twolintegral projecting vbrackets one at each `end of the'tube,.which secure the Y gas cylinder t'o-'abarrel 'I There is also an inte'`- gral' projecting lug'onvone end of thegascylinder,-fopposite the lower bracket. These projecting members interfere lwith conventional platingi apparatusl and therefore vnecessitate'aI unique iorrnpfplating vfixture for platingv the bore of the-gas cylinder. f l1 It is `an object of `this invention to provide an improvedlxture -tofconveniently hold the *gas cylinder of a rifle or articles of similarshape and to vplate the interior bore surface thereof'.

g It is a particular object of this invention to provide an improved plating lixture to plate the interior bore surface of a gas cylinder for the rie disclosed in U. S. Patent No. 2,198,610.

It is a, further object of this invention to provide a plating fixture for accommodating a plurality of gas cylinders.

The speciiic. nature of the invention as well as V, other objects and advantages thereof will clearly f taken along the plane 3-3 of Figi of a gas cylinder assembled to the platingixturel in position for plating the bore surface.

Fig.- 4 is an enlarged perspective View showing the friction device employed for obtaining ypositive electrical contact betweenfthe gas cylinder and the cathode.

Fig. 5 is an enlarged cross-sectional view showing the construction of the spacer used at the top 'of Athe;augure-'to lhold the bore of the glas cylinder concentrically about the anode.

A gas cylinder of the'type requiring plating issho'wn in Fig; 3, and comprises a cylindrical tube25, integrally vformed projecting brackets 1 and vvZlJ'orie at each end of tube y25,"an integral projectinfglug 128 opposite the bracket land projectin'ggslightly below the tube 25,v and any integrally" for'r'ned bayonet lug 21 projecting outwardly Vfrom the tube A25. The-projecting brackets'fand 26 arefnarrow cylindrical #bands which securethe cylinder tola'rie barrel (not shown).

The-bayonet lug 21 projects outwardlyfrom the y tube 25 on the outerwperiphery opposite to the brackets Tand 26 approximately inv the center of ftube 2li-and yis suitably shaped to receive aI lfor'medin'l a suitablehook shape 2 so that "the xture-maybe'suspended from the cathode-bar offanyi conventional1yr plating -apparatus (not shown). `"I'h'e other end -of tl'lecathode member I is bent to form a, short projecting member 3 at right angles to the cathode l. Attached to the member 3, as by means of the screw 5,`is a horizontal flat cathode plate 4, which is formed of conducting material, suchas metal. Near. the forward edge-and equally spaced on the metal plate 4 are small cylindrical cathode studs 6a,

. 6b, 6c and 6d.` These studs are somewhat smaller e in vdiameter than'the lower barrel bracket 1 of f der slightly abovel cathode plate 4, permitting a gas cylinder 8 and are secured to the metallic plate 4 by means of the screws 9a, 9b, 9c and 9d respectively. To insure good electrical contact between the cathode and the gas. cylinder, a

l.spring friction device I0 is inserted in a suitable slot I I provided in each of `the studs 6a, 6b, 6c, and 6d and are secured therein by the screws 9a, 9b, 9c, and 9d. The spring l0 protrudes sufciently beyond the outer periphery of each stud to provide suitable engagement with the barrel bracket 1 of gas cylinder 8. A shoulder 6e is provided atv the base of each stud on which the barrel .bracket rests, hence supporting the cylinready flow of electrolyte into the cylinder.

Immediately in` back of eachstud 6a, 6b, 6c

and 6d are placed anode rods 12a, |2b, I2c, and

IZd respectively. These anodes pass thru bushings I3 oi suitable electrical insulating material in the cathode plate 4 and are securely fastened to a horizontal anode bus I4 by means of the nuts l5 and I6, the nut I5 serving as a lock nut against which the anode bus I4 is firmly held by the nut I6. The bushings I3 may be secured in the cathode plate 4 by any suitable `means and the anodes Iza, I2b, I2c, and I2d may in turn be secured to the bushings I3 by threads or other suitable means. The anode rods I2a, I2b, I2c, and I2d are the same length as a gas cylinder 8. Attached to the upper end of the anode rods as by means of threads I'I are small cylindrical spacers I8 of suitable electrical insulating material to maintain the bore of the gas cylinder in concentric relation with the anode.'v These spacers are slightly smaller than the bore of gas cylinder in order that a gas cylinder may be easily slipped over the anode. Each spacer I8 is suitably grooved to permit free passage of a solution around the spacer and thru the bore of the gas cylinder. Two upwardly projecting pins ISa and ISb in the plate 4 lightly engage the projecting lug 20 on gas cylinder 8 and help maintain the lower end of the gas cylinder above the metallic plate 4. An anode terminal 2l is suitably formed and fastened to the anode bus I4 directly in back of the cathode I and is separated fromthe cathode by a block 22 of suitable electrical insulating material. The block 22 is fastened to the cathode I and anode terminal 2I by any suitable means as by the screws 23 and 24.

The fixture herein described is preferably used when chromium plating the bore of a gas cylinder. Plating the bore is accomplished by conventional electro-chemical plating solution and practice. Prior to plating, the gas cylinders are placed on the fixture, the anodes I2a, I2b, I2c, and I2d being within the respective cylinder bores, and the lower bracket 1 of each cylinder placed over the studs 6a, 6b, 6c, and 6d. When the lug 20 of each cylinder is positioned on the pins ISa, and I9b a suitable opening is left between the bottom ofthe cylinder and xture to provide free circulation of the plating-solution upwardly thru this bore of the cylinder.

zio

With this construction it is apparent that each gas cylinder is accurately positioned with respect to its anode and there is no need for time consuming centering operations.

While the fixture shown in Fig. 1 and described herein will accommodate only four gas cylinders at a time, it should be understood that is is within the scope of this invention to provide a fixture that will hold any desired number of gas cylinders within the limits of a xture of convenient size to handle.

I claim:

l. A fixture for plating the interior surface of a hollow cylinder having a radially depending bracket, said fixture comprising a metallic plate connected to the negative terminal of the electroplating current, a rod-like anode having one end secured to said plate but insulated therefrom, a spacer on the other end of the anode engaging the interior surface of the cylinder said spacer being formed of insulating material and having apertures therethrough to permit the flow of electrolyte through said cylinder, a stud mounted on said plate in xed relation to said anode, said stud being conductively connected to said plate and means on said stud adapted to conductively engage said bracket to hold said cylinder on said stud and in concentric relation with respect to said anode.

2. A xture for plating the interior surface of a hollow cylinder having a radially depending bracket, said fixture comprising a metallic plate connected to the negative terminal of the electroplating current, a rod-like anode having one end secured to said plate but insulated therefrom, a spacer on the other end of the anode engaging the interior surface of the cylinder said spacer being formed of insulating material and lprovided with apertures therethrough to permit the flow of electrolyte through said cylinder, means conductively mounted on said plate and inserted into said bracket to conductively engage said bracket to hold said cylinder in concentric relation With respect to said anode.

GEORGE KALISTA. 

